Description
Viscosity could be described as the flow of a liquid and is measured by centipoises (cps). Good viscosity properties are the key to maintaining the proper flow of cuttings out of the borehole. The yield of drilling fluids is typically compared by how many barrels (42 gal/bbl) of drilling fluid at 40-cps that one short ton (2000 lbs) of bentonite will make. Typically calcium bentonite yields about 35-45 bbl/ton. Some standard western sodium bentonite yields 90 bbl/ton minimum, while some advanced fluids yield over 200 bbl/ton. Even though some bentonites appear to be low cost, they might actually be more expensive when compared by actual yield. HD200 and SP200 have a significantly higher yield than API grade but price wise, the per bbl works out to be lower.
Typical Properties:
| Product | Yield (bbl/ton) | Fluid loss | Gel Strength (10min) |
|---|---|---|---|
| API 13A SEC 11 | 92 min | Max 15 | 10-12 |
| API 13A SEC 9 | 92 min | Max 16 | 10-12 |
| SP100 | 110 min | 16-18 | 15 |
| SP200 -(3%) -(4%) |
180 min 180 min |
16-18 16-18 |
16 31 |
| HD200 -(3%) -(4%) |
220 220 |
16-18 16-18 |
30 45 |
